• What is an EPTDS?
• Results of Water Quality Testing
• Distribution Zone Map

What is an EPTDS?

Water is moved from the wells to storage tanks in large diameter pipelines. The water is treated along the way. Treatment includes:

• Disinfection with sodium hypochlorite. Generated on-site from table salt and water, the product is like weak household bleach.
• Fluoridation to prevent dental cavities. On most of the east side of the Rio Grande, the Authority adds fluoride. In Distribution Zones 13 and 14, no fluoride is added. The water contains sufficient fluoride when it is pumped from the ground. Likewise, all of the water pumped on the west side of the river contains sufficient natural fluoride.

How Trunk Lines Work

From the valley to the heights, storage tanks are organized in trunks. Pump stations move treated water from one storage tank to another. The result is a mix of treated waters from many wells in each storage tank.

At the Entry Point to the Distribution System or the EPTDS, water from a storage tank enters the distribution system to deliver water to individual neighborhoods and customer taps by gravity flow. Specific EPTDS(s) provide water to each distribution zone. In some cases, treated water from an individual well enters the distribution system through a separate EPTDS. Water distributed within each distribution zone is of the same quality.

Water moves in trunk lines that run from low to high ground, and down major streets. Now, because of the San Juan-Chama Drinking Water Project, we have a system of north/south pipelines that connect all the trunk lines. They help distribute the treated surface water and water from low arsenic wells throughout the system, on both sides of the river.

Results of Water Quality Testing

The interactive map below is linked to tables that show the results of water quality testing. The Water Authority service area is outlined on the map. The blue lines on the map show the 19 distribution zones in the service area. Use the map to identify your distribution zone.

The table for each distribution zone gives a summary of water quality testing results for that zone and the average water quality testing results for the distribution system citywide. For each zone, there are two tables.

The first table shows the results of water quality testing to comply with drinking water quality regulations. Only the substances that were detected during compliance monitoring at EPTDS that feed a zone are listed in the table. The results for compliance monitoring for microbiological contaminants, disinfection by-products, and disinfectants measured throughout the distribution system are also listed on this web site. Substances that were not found in compliance monitoring are listed here.

The results of additional water quality testing for 2008 are summarized in the second table. These additional samples are collected to monitor the distribution system more frequently and for more substances than regulations require. Samples are collected in each distribution zone every three months.

Pilot Treatment Plant Results: Voluntary Monitoring

For information on Voluntary Monitoring Results for the Pilot Treatment Plant, visit Pilot Treatment Plant Results.